主題:register

In linguistics, a register is a variety of a language used for a particular purpose or in a particular social setting. For example, when speaking in a formal setting an English speaker may be more likely to adhere more closely to prescribed grammar, pronounce words ending in -ing with a velar nasal instead of an alveolar nasal (e.g. "walking", not "walkin'"), choose more formal words (e.g. father vs. dad, child vs. kid, etc.), and refrain from using the word ain't, than when speaking in an informal setting. (from wikipedia)